Azotostoma fusta J.L. Barnard, 1965

Lowry, J. K. & Stoddart, H. E., 2009, Lysianassidae *, Zootaxa 2260 (1), pp. 561-597 : 562-565

Azotostoma fusta J.L. Barnard, 1965

( Figs 1 , 2 , Pl. 4B)

Azotostoma fusta J.L. Barnard 1965: 485 , figs 1, 2. —? Ledoyer 1986: 732, fig. 281. — Barnard & Karaman 1991: 469.

Material examined. 2 unsexed, AM P68893 (EM 8.1c) ; 3 unsexed, AM P68891 and 1 female, 2.5 mm, AM P68919 ( JDT / LIZ 15 ) ; 1 unsexed, AM P68886 ( JML 16-10 - 7 ) ; 1 unsexed, AM P68887, ( JML 20-10 - 1 ) ; 1 unsexed, AM P68888 ( JML 20-10 - 2 ) ; 2 unsexed, AM P68889 and 1 female, 2.4 mm, AM P68918 ( JML 81- 26 - 11-4 ) ; 1 unsexed, AM P68890 ( JML 83-4 - 3-11 ) ; 1 female, AM P68894 ( NCL 112 ) ; 5 unsexed, AM P68895 ( NCL 155 ) ; 1 unsexed, AM P68892 ( QLD 95 ) ; 1 unsexed, AM P70557 ( QLD 1618 ) ; 1 unsexed ( SEL /LZI-1-3).

Type locality. Ifaluk Atoll , Caroline Islands, Micronesia, western North Pacific Ocean (~ 7°15'N 144°27'E) .

Description. Based on female, 2.4 mm, AM P68918 and female, 2.5 mm, AM P68919.

Head and body without scattered setae. Body not expanded to form a lateral bulge, without dorsal carina. Head lateral cephalic lobes a semidome, with apically rounded margins; eyes round. Antenna 1 subequal to antenna 2; flagellum article 1 slightly longer than article 2; without callynophore, robust setae absent from proximal articles; calceoli absent; accessory flagellum with 2 articles. Antenna 2 less than 40% of body length; peduncle without brush setae, peduncular article 3 elongate, at least 2.5 x as long as broad; calceoli absent. Mouthparts forming a conical bundle. Epistome / upper lip fused, broadly rounded. Mandible molar absent; palp attached extremely proximally, article 3 without A3–setae. Maxilla 1 inner plate with many fine apical setae; outer plate with setal-teeth in 6/5 arrangement; setal-tooth 7, left and right symmetrical, slightly cuspidate distally; palp distal margin with weak serrations. Maxilliped inner plates well developed, as long as outer plates; outer plates with 2 short slender apical robust setae; palp 4–articulate, article 4 large, article 2 projecting medially, article 3 inserted midway along anterior margin of article 2.

Pereon. Gnathopod 1 simple, extremely attenuated; coxa large, about as long as coxa 2, subrectangular with slightly concave anterior margin; basis without setae along anterior margin; ischium short; carpus short (length 1.5 x breadth), distinctly shorter than propodus, without posterior lobe; propodus longer than broad, margins tapering; dactylus inner margin minutely serrated. Gnathopod 2 subchelate; carpus longer than propodus; palm transverse; dactylus minute. Pereopod 3 propodus with blunt, locking robust seta at posterodistal corner. Pereopod 4 coxa with well developed posteroventral lobe; propodus with blunt, locking robust seta at posterodistal corner. Pereopod 5 coxa equilobate; basis distinctly broader than long.

Pleon. Epimeron 1 anterodistal corner broadly rounded. Epimeron 3 posterior margin smooth, posterodistal corner produced, forming a small spine. Urosomite 1 without dorsal depression, dorsally straight. Urosomites 2 and 3 fused. Uropod 1 rami subequal. Uropod 2 rami subequal, inner ramus without marginal constriction. Uropod 3 without plumose setae on rami; outer ramus 1–articulate. Telson slightly longer than broad, entire, without dorsal robust setae.

Habitat. Algae, coral rubble, fine sands and plankton at night, intertidal to 12 m depth.

Remarks. Azotostoma fusta is an unusual lysianassine with very specialized mouthparts. It can be separated from all other lysianassids on the reef by its conical mouthpart bundle and by its attenuated, simple first gnathopods. Another species, A. bunakenensis Ortiz & Lalana, 1997 , has been reported from eastern Indonesia. They differ in: the dactylus of the first gnathopods, which is minutely serrated in A. fusta and smooth in A. bunakenensis ; the telson, which is about as long as broad in A. fusta and longer than broad in A. bunakenensis ; the inner plate of the second maxilla, which is greatly expanded in A. fusta and apparently subequal to the outer plate in A. bunakenensis ; and the first maxilla outer plate, which has eleven setal-teeth in A. fusta and reportedly seven in A. bunakenensis .

Ledoyer’s (1986) record of A. fusta from Madagascar might represent a separate species, based on the shape of the lateral cephalic lobe and the shape of pereopod 7 basis.

Distribution. Australia. Queensland: Lizard Island; Carter Reef; Dingo Beach near Bowen (current study). Tasman Sea: Middleton Reef (current study).? Madagascar. Nosy-Be ( Ledoyer 1986). Micronesia. Ifaluk Atoll, Caroline Islands (J.L. Barnard 1965). New Caledonia. Îlot des Goelands and Grand Récif Abore; Grand Récif Mbere (current study).

Figures

FIGURE 1. Azotostoma fusta J.L. Barnard, 1965, female, 2.5 mm, AM P68919, Lizard Head, Lizard Island, Great Barrier Reef; U3 and T: female, 2.4 mm, AM P68918, between Lizard and Carter Reefs, Lizard Island, Great Barrier Reef.

FIGURE 2. Azotostoma fusta J.L. Barnard, 1965, female, 2.4 mm, AM P68918, between Lizard and Carter Reefs, Lizard Island, Great Barrier Reef; G1 and G2 enlargements: female, 2.5 mm, AM P68919, Lizard Head, Lizard Island, Great Barrier Reef.